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)
Message- > From: users-boun...@open-mpi.org > [mailto:users-boun...@open-mpi.org] On Behalf Of Troy Telford > Sent: Thursday, June 01, 2006 7:24 PM > To: us...@open-mpi.org > Subject: [OMPI users] Open MPI and Dual Core (machinefile) > > I'm hoping this is just

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

2006-06-01 Thread Troy Telford
I'm hoping this is just user error... I'm running a single-node job with a node that has two dual-core opterons (Open MPI 1.0.2). compiler=gcc 4.1.0 arch=x86_64 (64-bit) OS=linux 2.6.16 My machine file looked like this: node1 slots=4 I have an HPL configuration for 4 processors (PxQ=2