Thank you, Ralph for the detailed explanation. On Thu, May 19, 2016 at 7:36 PM, Ralph Castain <r...@open-mpi.org> wrote:
> No!! A “slot” is purely a bookkeeping construct that schedulers use to > tell you how many procs you can run. It has nothing to do with a core or > any other physical resource. > > It is true that we generally configure our schedulers to set the max > #slots on each node to equal the #cores on the node - but that is purely a > configuration choice. > > > On May 19, 2016, at 4:29 PM, Saliya Ekanayake <esal...@gmail.com> wrote: > > Thank you, Tetsuya. So is a slot = core? > > On Thu, May 19, 2016 at 7:26 PM, <tmish...@jcity.maeda.co.jp> wrote: > >> Hi Saliya and Ralph, >> >> I guess Ralph is confusing "bind-to core" with "bind-to slot". >> >> As far as I remember, when you add "PE=N" option to the map-by directive, >> you can only use "bind to slot". >> >> So if you want to bind a process to specific slots(almost same as cores), >> you should use "bind-to slot". >> >> Regards, >> Tetsuya >> >> 2016/05/20 5:03:27、"users"さんは「Re: [OMPI users] The effect of --bind-to >> in the presence of PE=N in --map-by」で書きました >> > So if bind-to-core is in effect, does that mean it'll run only on 1 core >> even though I'd like it to be able to utilize 4 cores. For examples, I'll >> be creating 4 threads within the process and would >> > like to pin them to each core the process has been bound to. >> > >> > On Thu, May 19, 2016 at 3:46 PM, Ralph Castain <r...@open-mpi.org>wrote: >> > Perhaps we should error out, but at the moment, PE=4 forces bind-to-core >> and so the bind-to socket is being ignored >> > >> > On May 19, 2016, at 12:06 PM, Saliya Ekanayake <esal...@gmail.com> >> wrote: >> > >> > Hi, >> > >> > I understand --map-by will determine the process placement whereas >> --bind-to will keep the processes pinned to the given resource. If this >> understanding is correct, then I've got a doubt with the >> > following. >> > >> > On a node with 2 sockets and 12 cores each, >> > >> > --map-by ppr:3:socket,PE=4 --bind-to socket >> > >> > My understanding is that this will give each process 4 cores. Now, with >> bind to socket, does that mean it's possible that within a socket the >> assgined 4 cores for a process may change? Or will they >> > stay in the same 4 cores always? >> > >> > Thank you, >> > Saliya >> > >> > -- >> > Saliya Ekanayake >> > Ph.D. Candidate | Research Assistant >> > School of Informatics and Computing | Digital Science Center >> > Indiana University, Bloomington >> > >> > >> > _______________________________________________ >> > users mailing list >> > us...@open-mpi.org >> > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users >> > Link to this post: >> http://www.open-mpi.org/community/lists/users/2016/05/29243.php >> > >> > >> > _______________________________________________ >> > users mailing list >> > us...@open-mpi.org >> > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users >> > Link to this post: >> http://www.open-mpi.org/community/lists/users/2016/05/29244.php >> > >> > >> > >> > -- >> > Saliya Ekanayake >> > Ph.D. Candidate | Research Assistant >> > School of Informatics and Computing | Digital Science Center >> > Indiana University, Bloomington >> > >> > _______________________________________________ >> > users mailing list >> > us...@open-mpi.org >> > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/usersLink >> to >> this post: >> http://www.open-mpi.org/community/lists/users/2016/05/29245.php >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users >> Link to this post: >> http://www.open-mpi.org/community/lists/users/2016/05/29248.php > > > > > -- > Saliya Ekanayake > Ph.D. Candidate | Research Assistant > School of Informatics and Computing | Digital Science Center > Indiana University, Bloomington > > _______________________________________________ > users mailing list > us...@open-mpi.org > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2016/05/29249.php > > > > _______________________________________________ > users mailing list > us...@open-mpi.org > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2016/05/29251.php > -- Saliya Ekanayake Ph.D. Candidate | Research Assistant School of Informatics and Computing | Digital Science Center Indiana University, Bloomington
