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From: Ralph Castain (rhc_at_[hidden])
Date: 2006-06-02 11:41:30

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 into it.


Troy Telford wrote:
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 that 'cpuinfo' simply returns what the CPU  
reports... so the CPU knows it's dual-core, and reports this.  That  
doesn't mean Linux has to recognize that there are really 4 CPUs...

So, problem solved (at least from Open MPI's standpoint...)