Agreed - Jeff and I discussed this just this morning. I will be updating FAQ soon
Sent from my iPhone > On Mar 27, 2014, at 9:24 AM, Gus Correa <g...@ldeo.columbia.edu> wrote: > > <\begin hijacking this thread> > > I second Saliya's thanks to Tetsuya. > I've been following this thread, to learn a bit more about > how to use hardware locality with OpenMPI effectively. > [I am still using "--bycore"+"--bind-to-core" in most cases, > and "--cpus-per-proc" occasionally when in hybrid MPI+OpenMP mode.] > > When it comes to hardware locality, > the syntax and the functionality has changed fast and significantly > in the recent past. > Hence, it would be great if the OpenMPI web page could provide pointers > for the type of external documentation that Tetsuya just sent. > Perhaps also some additional guidelines and comments > on what is available on each release/series of OpenMPI, > and how to use these options. > > There is some material about hwloc, > but I can't see much about lama ( which means "mud" in my > first language :) ). > We can hardly learn things like that from the mpiexec man page > alone, although it has very good examples. > > Thank you, > Gus Correa > > <\end hijacking of this thread> > >> On 03/27/2014 11:38 AM, Saliya Ekanayake wrote: >> Thank you, this is really helpful. >> >> Saliya >> >> >> On Thu, Mar 27, 2014 at 5:11 AM, <tmish...@jcity.maeda.co.jp >> <mailto:tmish...@jcity.maeda.co.jp>> wrote: >> >> >> >> Mapping and binding is related to so called process affinity. >> It's a bit difficult for me to explain ... >> >> So please see this URL below(especially the first half part >> of it - from 1 to 20 pages): >> >> http://www.slideshare.net/jsquyres/open-mpi-explorations-in-process-affinity-eurompi13-presentation >> >> Although these slides by Jeff are the explanation for LAMA, >> which is another mapping system installed in the openmpi-1.7 >> series, I guess you can easily understand what is mapping and >> binding in general terms. >> >> Tetsuya >> >> > Thank you Tetsuya - it worked. >> > >> > Btw. what's the difference between mapping and binding? I think I >> am bit >> confused here. >> > >> > Thank you, >> > Saliya >> > >> > >> > On Thu, Mar 27, 2014 at 4:19 AM, <tmish...@jcity.maeda.co.jp >> <mailto:tmish...@jcity.maeda.co.jp>>wrote: >> > >> > >> > Hi Saliya, >> > >> > What you want to do is map-by node. So please try below: >> > >> > -np 2 --map-by node:pe=4 --bind-to core >> > >> > You might not need to add --bind-to core, because it's default >> binding. >> > >> > Tetsuya >> > >> > > Hi, >> > > >> > > I see in v.1.7.5rc5 --cpus-per-proc is deprecated and is advised to >> > replace by --map-by <obj>:PE=N. >> > > I've tried this but I couldn't get the expected allocation of >> procs. >> > > >> > > For example I was running 2 procs on 2 nodes each with 2 >> sockets where >> a >> > socket has 4 cores. I wanted 1 proc per node and bound to all >> cores in >> one >> > of the sockets. I could get this by using >> > > >> > > --bind-to core: --map-by ppr:1:node --cpus-per-proc 4 -np 2 >> > > >> > > Then it'll show bindings as >> > > >> > > [i51:32274] MCW rank 0 bound to socket 0[core 0[hwt 0]], socket >> 0[core >> 1 >> > [hwt 0]], socket 0[core 2[hwt 0]], socket 0[core 3[hwt 0]]: >> > [B/B/B/B][./././.] >> > > [i52:31765] MCW rank 1 bound to socket 0[core 0[hwt 0]], socket >> 0[core >> 1 >> > [hwt 0]], socket 0[core 2[hwt 0]], socket 0[core 3[hwt 0]]: >> > [B/B/B/B][./././.] >> > > >> > > >> > > Is there a better way without using -cpus-per-proc as suggested >> to get >> > the same effect? >> > > >> > > Thank you, >> > > Saliya >> > > >> > > >> > > >> > > -- >> > > Saliya Ekanayake esal...@gmail.com <mailto:esal...@gmail.com> >> > > Cell 812-391-4914 <tel:812-391-4914> Home 812-961-6383 >> <tel:812-961-6383> >> > > http://saliya.org_______________________________________________ >> > > users mailing list >> > > >> users@open-mpi.orghttp://www.open-mpi.org/mailman/listinfo.cgi/users >> <http://www.open-mpi.org/mailman/listinfo.cgi/users> >> > >> > _______________________________________________ >> > users mailing list >> > us...@open-mpi.org <mailto:us...@open-mpi.org> >> > http://www.open-mpi.org/mailman/listinfo.cgi/users >> > >> > >> > >> > -- >> > Saliya Ekanayake esal...@gmail.com <mailto:esal...@gmail.com> >> > Cell 812-391-4914 <tel:812-391-4914> Home 812-961-6383 >> <tel:812-961-6383> >> > http://saliya.org_______________________________________________ >> > users mailing list >> > >> users@open-mpi.orghttp://www.open-mpi.org/mailman/listinfo.cgi/users >> <http://www.open-mpi.org/mailman/listinfo.cgi/users> >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org <mailto:us...@open-mpi.org> >> http://www.open-mpi.org/mailman/listinfo.cgi/users >> >> >> >> >> -- >> Saliya Ekanayake esal...@gmail.com <mailto:esal...@gmail.com> >> Cell 812-391-4914 Home 812-961-6383 >> http://saliya.org >> >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
