Re: [OMPI users] Open MPI and Dual Core (machinefile)

2006-06-02 Thread Troy Telford
On Fri, 02 Jun 2006 09:41:30 -0600, Ralph Castain wrote: I don't remember if it has to be explicitly enabled or not - or if it only started with a particular 2.6.x release. You might want to check into it. There are other factors invovled as well (BIOS settings, for instance). The kerne

Re: [OMPI users] Open MPI and Dual Core (machinefile)

2006-06-02 Thread Ralph Castain
Hi Troy I'm not sure what iteration of Linux you are using, but the 2.6 kernel has multi-core scheduling support that is supposed to resolve this problem. I don't remember if it has to be explicitly enabled or not - or if it only started with a particular 2.6.x release. You might want to check

Re: [OMPI users] Open MPI and Dual Core (machinefile)

2006-06-02 Thread Troy Telford
On Fri, 02 Jun 2006 09:15:06 -0600, Troy Telford wrote: Can you confirm that your Linux installation thinks that it has 4 processors and will schedule 4 processes simultaneously? D'oh. Still too early in the morning... OK, Linux thinks it has two CPUs. Period. For some reason I forgot tha

Re: [OMPI users] Open MPI and Dual Core (machinefile)

2006-06-02 Thread Troy Telford
On Thu, 01 Jun 2006 18:07:07 -0600, Jeff Squyres (jsquyres) wrote: This *sounds* like the classic oversubscription problem: Open MPI's aggressive vs. degraded operating modes: http://www.open-mpi.org/faq/?category=running#oversubscribing Good link; bookmarked for (internal) documentation..

Re: [OMPI users] Open MPI and Dual Core (machinefile)

2006-06-01 Thread Jeff Squyres (jsquyres)
This *sounds* like the classic oversubscription problem: Open MPI's aggressive vs. degraded operating modes: http://www.open-mpi.org/faq/?category=running#oversubscribing Specifically, "slots" is *not* meant to be the number of processes to run. It's meant to be how many processors are available