Ok, but in Ompi 1.3 how can i enable it? 2008/11/18 Ralph Castain <r...@lanl.gov>: > I am afraid it is only available in 1.3 - we didn't backport it to the 1.2 > series > > > On Nov 18, 2008, at 10:06 AM, Gabriele Fatigati wrote: > >> Hi, >> how can i set "slot mapping" as you told me? With TASK GEOMETRY? Or is >> a new 1.3 OpenMPI feature? >> >> Thanks. >> >> 2008/11/18 Ralph Castain <r...@lanl.gov>: >>> >>> Unfortunately, paffinity doesn't know anything about assigning threads to >>> cores. This is actually a behavior of Linux, which only allows paffinity >>> to >>> be set at the process level. So, when you set paffinity on a process, you >>> bind all threads of that process to the specified core(s). You cannot >>> specify that a thread be given a specific core. >>> >>> In this case, your two threads/process are sharing the same core and thus >>> contending for it. As you'd expect in that situation, one thread gets the >>> vast majority of the attention, while the other thread is mostly idle. >>> >>> If you can upgrade to the beta 1.3 release, try using the slot mapping to >>> assign multiple cores to each process. This will ensure that the threads >>> for >>> that process have exclusive access to those cores, but will not bind a >>> particular thread to one core - the threads can "move around" across the >>> specified set of cores. Your threads will then be able to run without >>> interfering with each other. >>> >>> Ralph >>> >>> >>> On Nov 18, 2008, at 9:18 AM, Gabriele Fatigati wrote: >>> >>>> Dear OpenMPI developers, >>>> i have a strange problem with mixed program MPI+OPENMP over OpenMPI >>>> 1.2.6. I'm using PJL TASK GEOMETRY in LSF Scheduler, setting 2 MPI >>>> process every compute node, and 2 OMP threads per process. Using >>>> paffinity and maffinity, i've noted that over every node, i have 2 >>>> thread that works 100%, and 2 threads doesn't works, or works very >>>> few. >>>> >>>> If i disable paffinity and maffinity, 4 threads works well, without >>>> load imbalance. >>>> I don't understand this issue: paffinity and maffinity should map >>>> every thread over a specific core, optimizing the cache flow, but i >>>> have this without settings there! >>>> >>>> Can i use paffinity and maffinity in mixed MPI+OpenMP program? Or it >>>> works only over MPI thread? >>>> >>>> Thanks in advance. >>>> >>>> >>>> -- >>>> Ing. Gabriele Fatigati >>>> >>>> CINECA Systems & Tecnologies Department >>>> >>>> Supercomputing Group >>>> >>>> Via Magnanelli 6/3, Casalecchio di Reno (BO) Italy >>>> >>>> www.cineca.it Tel: +39 051 6171722 >>>> >>>> g.fatig...@cineca.it >>>> _______________________________________________ >>>> 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 >>> >>> >> >> >> >> -- >> Ing. Gabriele Fatigati >> >> CINECA Systems & Tecnologies Department >> >> Supercomputing Group >> >> Via Magnanelli 6/3, Casalecchio di Reno (BO) Italy >> >> www.cineca.it Tel: +39 051 6171722 >> >> g.fatig...@cineca.it >> _______________________________________________ >> 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 > >
-- Ing. Gabriele Fatigati CINECA Systems & Tecnologies Department Supercomputing Group Via Magnanelli 6/3, Casalecchio di Reno (BO) Italy www.cineca.it Tel: +39 051 6171722 g.fatig...@cineca.it
