Not really. When you add PE=N, then you are asking us to assign each proc to N cpus. Thus, we have no other option but to bind you to cpu - otherwise we cannot honor that request. So in the absence of the —use-hwthread-cpus, we are going to bind you to 4 cores.
There is no “bind-to slot” as a slot is an artifice of scheduling - there is no physical “slot” we can bind someone to. We can “map-by slot” - just can’t bind you to something that doesn’t actually exist. > On May 19, 2016, at 4:26 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
