To exclude a possible bug within the LSF component, I rebuilt Open MPI without support for LSF (--without-lsf).
-> It makes no difference - the latency is still bad: ~1.1us. Matthias On Friday 02 March 2012 13:50:13 Matthias Jurenz wrote: > SORRY, it was obviously a big mistake by me. :-( > > Open MPI 1.5.5 was built with LSF support, so when starting an LSF job it's > necessary to request at least the number of tasks/cores as used for the > subsequent mpirun command. That was not the case - I forgot the bsub's '-n' > option to specify the number of task, so only *one* task/core was > requested. > > Open MPI 1.4.5 was built *without* LSF support, so the supposed misbehavior > could not happen with it. > > In short, there is no bug in Open MPI 1.5.x regarding to the detection of > oversubscription. Sorry for any confusion! > > Matthias > > On Tuesday 28 February 2012 13:36:56 Matthias Jurenz wrote: > > When using Open MPI v1.4.5 I get ~1.1us. That's the same result as I get > > with Open MPI v1.5.x using mpi_yield_when_idle=0. > > So I think there is a bug in Open MPI (v1.5.4 and v1.5.5rc2) regarding to > > the automatic performance mode selection. > > > > When enabling the degraded performance mode for Open MPI 1.4.5 > > (mpi_yield_when_idle=1) I get ~1.8us latencies. > > > > Matthias > > > > On Tuesday 28 February 2012 06:20:28 Christopher Samuel wrote: > > > On 13/02/12 22:11, Matthias Jurenz wrote: > > > > Do you have any idea? Please help! > > > > > > Do you see the same bad latency in the old branch (1.4.5) ? > > > > > > cheers, > > > Chris > > > > _______________________________________________ > > devel mailing list > > de...@open-mpi.org > > http://www.open-mpi.org/mailman/listinfo.cgi/devel > > _______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel
