and MPI in one Computer Dual Core???

Discussion:

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ADMINISTRADOR

2009-05-28 20:31:15 UTC

Hi!

Im trying to run mpi in a Intel Core 2 Duo machine, and i dont know
how to edit the /etc/hosts file so i can establish two nodes - in same
computer! - and get fully performance of my laptop.

my etc/hosts looks like
127.0.0.1 localhost
127.0.1.1 laptop

my .mpd.hosts is
localhost
laptop

But obviously doesnt work... Is there any possible solution to my
request?

Thanks in advance!

Alejandro Santa-Cruz
UPM

Adrie K

2009-05-29 10:19:33 UTC

Permalink

Post by ADMINISTRADOR
Hi!
Im trying to run mpi in a Intel Core 2 Duo machine, and i dont know
how to edit the /etc/hosts file so i can establish two nodes - in same
computer! - and get fully performance of my laptop.
my etc/hosts looks like
127.0.0.1 localhost
127.0.1.1 laptop
my .mpd.hosts is
localhost
laptop
But obviously doesnt work... Is there any possible solution to my
request?

...

I used a mpihosts file like this:

machine1
machine2
machine3
machine1
machine1

to get an uneven distributed load to different machines.
Three processes will run on machine1, the os will take care
of using multiple cores.
I guess the operating system of machine1 in this case will

I did not do any exhaustive testing, but it seems to work well
this way.

Good luck!

ADMINISTRADOR

2009-05-29 12:22:48 UTC

Permalink

Post by Adrie K

...
machine1
machine2
machine3
machine1
machine1
to get an uneven distributed load to different machines.
Three processes will run on machine1, the os will take care
of using multiple cores.
I guess the operating system of machine1 in this case will
I did not do any exhaustive testing, but it seems to work well
this way.
Good luck!

This is coupled run. Total number of pe is 1
PE 0 :********* Error stop in rmpinit *********
PE 0 :error code from mpi_init = 0
PE 0 :error code from mpi_comm_size = 0
PE 0 :error code from mpi_comm_rank = 0
PE 0 :npes preset in code = 2
PE 0 :npes request from environment = 1
PE 0 :******* End of output for mpinit *******
p0_7696: p4_error: : 1
[0] MPI Abort by user Aborting program !
[0] Aborting program!

santacruz

2009-05-29 12:35:15 UTC

Permalink

Post by Adrie K

Hi

I am running an application that is compiled with mpif90 and mpicc,
and the problem comes when a function makes an
mpi_comm_size(mpi_comm_x,NPES,ierr)
so its looking for the number of processes to use in order to run the
app. I configured it to use 2 different nodes, as i have a dual core,
but when it comes to that funct this error occurs:

This is coupled run. Total number of pe is 1
PE 0 :********* Error stop in rmpinit *********
...
PE 0 :npes preset in code = 2
PE 0 :npes request from environment = 1
PE 0 :******* End of output for mpinit *******
p0_7696: p4_error: : 1
[0] MPI Abort by user Aborting program !
[0] Aborting program!

So, my main point is trying to get the machine to recognize 2 nodes,
as both npes should be the same and equal to 2.

By typing mpiexec -n 2 EXAMPLE i get two processes working on that
example, so now what i am trying is to set a ring of nodes so they can
communicate, with:
mpdboot -n 2 -f .mpd.hosts
totalnum=2 numhosts=1
there ar enot enough hosts on which to start all process

So that makes me think mpdboot is only to use when you have several
machines with different hostnames...?¿

.mpd.hosts has been in all these forms:

laptop:2
***l
laptop:1
laptop:1
***
laptop1
laptop2
***
laptop
localhost

and with this last one it did launch the daemons on portatil, but it
failed to handsake with mpd on localhost
i dont know if im missing some theory about the use of the functions..
or what im trying to do its impossible, or even its the application
that is going wrong...

thanks for reading!