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Subject: Re: [OMPI users] dual cores
From: Brock Palen (brockp_at_[hidden])
Date: 2008-11-10 00:21:45


Run 'top' For long running applications you should see 4 processes
each at 50% (4*50=200% two cpus).

You are ok, your hello_c did what it should, each of thoese 'hello's
could have came from any of the two cpus.

Also if your only running on your local machine, you don't need a
hostfile, and -byslot is meaningless in this case,

mpirun -np 4 ./hello_c

Would work just fine.

Brock Palen
www.umich.edu/~brockp
Center for Advanced Computing
brockp_at_[hidden]
(734)936-1985

On Nov 10, 2008, at 12:05 AM, Hodgess, Erin wrote:

> Dear Open MPI gurus:
>
> I have just installed Open MPI this evening.
>
> I have a dual core laptop and I would like to have both cores running.
>
> Here is the following my-hosts file:
> localhost slots=2
>
> and here is the command and output:
> mpirun --hostfile my-hosts -np 4 --byslot hello_c |sort
> Hello, world, I am 0 of 4
> Hello, world, I am 1 of 4
> Hello, world, I am 2 of 4
> Hello, world, I am 3 of 4
> hodgesse_at_erinstoy:~/Desktop/openmpi-1.2.8/examples>
>
>
> How do I know if both cores are running, please?
>
> thanks,
> Erin
>
>
> Erin M. Hodgess, PhD
> Associate Professor
> Department of Computer and Mathematical Sciences
> University of Houston - Downtown
> mailto: hodgesse_at_[hidden]
>
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