> On Dec 22, 2014, at 10:45 AM, Saliya Ekanayake <esal...@gmail.com> wrote: > > Hi Ralph, > > Yes the report bindings show the correct binding as expected for the > processes. The doubt I am having is, say I spawn a thread within my process. > If I don't specify affinity for it, is it possible for it to get scheduled to > run in a core outside that of the process?
It shouldn’t, unless you deliberately unbind it. > > Second question is, does MPI provides an API such that I can retrieve the > binding info from program to take decisions on setting thread affinity? Nothing specifically in the standard, no. There has been some discussion on this list about ways of getting the info, though they all involve a collective operation. I’m working on an MPI extension for OMPI to access it as each proc already has binding/location info for every proc in the job - just no MPI standard way of providing it to you. > > Thank you, > Saliya > > On Mon, Dec 22, 2014 at 1:18 PM, Ralph Castain <r...@open-mpi.org > <mailto:r...@open-mpi.org>> wrote: > FWIW: it looks like we are indeed binding to core if PE is set, so if you are > seeing something different, then we may have a bug somewhere. > > If you add —report-bindings to your cmd line, you should see where we bound > the procs - does that look correct? > > >> On Dec 22, 2014, at 9:49 AM, Ralph Castain <r...@open-mpi.org >> <mailto:r...@open-mpi.org>> wrote: >> >> They will be bound to whatever level you specified - I believe by default we >> bind to socket when mapping by socket. If you want them bound to core, you >> might need to add —bind-to core. >> >> I can take a look at it - I *thought* we had reset that to bind-to core when >> PE=N was specified, but maybe that got lost. >> >> >>> On Dec 22, 2014, at 8:32 AM, Saliya Ekanayake <esal...@gmail.com >>> <mailto:esal...@gmail.com>> wrote: >>> >>> Hi, >>> >>> I've been using --map-by socket:PE=N, where N is used to control the number >>> of cores a proc gets mapped to. Does this also guarantee that a proc is >>> bound to N cores in the socket? I am asking this because I see some threads >>> spawned by the process run outside the given N cores in the socket. >>> >>> Is this expected or I guess I am missing some binding parameter here? Also, >>> is there some documentation on these different choices? Are the options in >>> [1] available in current release? >>> >>> [1] >>> http://www.slideshare.net/jsquyres/open-mpi-explorations-in-process-affinity-eurompi13-presentation >>> >>> <http://www.slideshare.net/jsquyres/open-mpi-explorations-in-process-affinity-eurompi13-presentation> >>> >>> Thank you, >>> Saliya >>> >>> -- >>> Saliya Ekanayake >>> Ph.D. Candidate | Research Assistant >>> School of Informatics and Computing | Digital Science Center >>> Indiana University, Bloomington >>> Cell 812-391-4914 <tel:812-391-4914> >>> http://saliya.org >>> <http://saliya.org/>_______________________________________________ >>> users mailing list >>> us...@open-mpi.org <mailto:us...@open-mpi.org> >>> Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users >>> <http://www.open-mpi.org/mailman/listinfo.cgi/users> >>> Link to this post: >>> http://www.open-mpi.org/community/lists/users/2014/12/26051.php >>> <http://www.open-mpi.org/community/lists/users/2014/12/26051.php> > > > _______________________________________________ > users mailing list > us...@open-mpi.org <mailto:us...@open-mpi.org> > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users > <http://www.open-mpi.org/mailman/listinfo.cgi/users> > Link to this post: > http://www.open-mpi.org/community/lists/users/2014/12/26054.php > <http://www.open-mpi.org/community/lists/users/2014/12/26054.php> > > > > -- > Saliya Ekanayake > Ph.D. Candidate | Research Assistant > School of Informatics and Computing | Digital Science Center > Indiana University, Bloomington > Cell 812-391-4914 > http://saliya.org > <http://saliya.org/>_______________________________________________ > users mailing list > us...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2014/12/26056.php
