Le 04/09/2015 00:36, Gilles Gouaillardet a écrit : > Ralph, > > just to be clear, your proposal is to abort if openmpi is configured > with --without-hwloc, right ? > ( the --with-hwloc option is not removed because we want to keep the > option of using an external hwloc library ) > > if I understand correctly, Paul's point is that if openmpi is ported > to a new architecture for which hwloc has not been ported yet > (embedded hwloc or external hwloc), then the very first step is to > port hwloc before ompi can be built. > > did I get it right Paul ? > > Brice, what would happen in such a case ? > embedded hwloc cannot be built ? > hwloc returns little or no information ?
If it's a new operating system and it supports at least things like sysconf, you will get a Machine object with one PUs per logical processor. If it's a new platform running Linux, they are supposed to tell Linux at least package/core/thread information. That's what we have for ARM for instance. Missing topology detection can be worked around easily (with XML and synthetic description, what we did for BlueGene/Q before adding manual support for that specific processor). Binding support can't. And once you get binding, you get x86-topology even if the operating system isn't supported (using cpuid). > for example, on Fujitsu FX10 node (single socket, 16 cores), hwloc > reports 16 sockets with one core each and no cache. though this is not > correct, that can be seen as equivalent to the real config by ompi, so > this is not really an issue for ompi. Can you help fixing this? The issue is indeed with supercomputers with uncommon architectures like this one. Brice > > Cheers, > > Gilles > > On Friday, September 4, 2015, Ralph Castain <r...@open-mpi.org > <mailto:r...@open-mpi.org>> wrote: > > No - hwloc is embedded in OMPI anyway. > >> On Sep 3, 2015, at 11:09 AM, Paul Hargrove <phhargr...@lbl.gov >> <javascript:_e(%7B%7D,'cvml','phhargr...@lbl.gov');>> wrote: >> >> >> On Thu, Sep 3, 2015 at 8:03 AM, Ralph Castain <r...@open-mpi.org >> <javascript:_e(%7B%7D,'cvml','r...@open-mpi.org');>> wrote: >> >> Does anyone know of a reason why we shouldn’t do this? >> >> >> >> Would doing this mean that a port to a new system would require >> that one first perform a full hwloc port? >> >> -Paul >> >> -- >> Paul H. Hargrove phhargr...@lbl.gov >> <javascript:_e(%7B%7D,'cvml','phhargr...@lbl.gov');> >> Computer Languages & Systems Software (CLaSS) Group >> Computer Science Department Tel: +1-510-495-2352 >> Lawrence Berkeley National Laboratory Fax: +1-510-486-6900 >> _______________________________________________ >> devel mailing list >> de...@open-mpi.org >> <javascript:_e(%7B%7D,'cvml','de...@open-mpi.org');> >> Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel >> Link to this post: >> http://www.open-mpi.org/community/lists/devel/2015/09/17942.php > > > > _______________________________________________ > devel mailing list > de...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > Link to this post: > http://www.open-mpi.org/community/lists/devel/2015/09/17952.php
