Problems with MPI and inlet_test

[mistral]

Hello everybody

I can't use ROMS very well , but till now I have run in a correct way several Test-case bot idealized and realistic case .
Now I to work whit ROMS and SWAN coupled but for personal need I must set the work on my laptop first (intel dual core processor / Ubuntu 9.04 ).
At present I have compiled MCT and MPI (gfortran compiler) .
I have modified Linux-gfortran.mk editing this code lines :

ifdef USE_MCT

# MCT_INCDIR = /home/my/MCT/mct
# MCT_LIBDIR = /home/my/MCT/mct
# FFLAGS += -I$(MCT_INCDIR)
# LIBS += -L$(MCT_LIBDIR) -lmct -lmpeu

FFLAGS += -I/home/my/MCT/mct -I/home/my/MCT/mct/mpeu
MCT_LIBDIR ?= /home/my/MCT/mct
MPEU_LIBDIR ?= /home/my/MCT/mpeu
LIBS += -L$(MCT_LIBDIR) -lmct -L$(MPEU_LIBDIR) -lmpeu

and the build.sh in this way :

setenv USE_MPI on
setenv USE_MPIF90 o
setenv FORT gfortran

# setenv USE_DEBUG
# setenv USE_ARPACK
setenv USE_LARGE on

Then I have compiled the test case LAKE_SIGNELL , (including # define MPI) .
I have run it using : mpirun -np 2 oceanM ocean_lake_signell.in

in this way run work correctly on 1 core and not on both (2) of then as expected .
What is the problem???
What should I do to start “run” on both cores???
I have then tried to use the TEST_HEAD whit :

mpirun -np 2 oceanM coupling_test_head.in

but it didn't work and I have received this error :

mpirun -np 2 oceanM coupling_test_head.in

Coupled Input File name = coupling_test_head.in

MOD_COUPLER - Number assigned processors: 001
not equal to spawned MPI nodes: 001


would you please help me to solve my problems???
Best Regards

[kate]

Can you run ROMS alone with MPI on two cores?

[mistral]

i can do it with one core (in lake_signell test case , and in test_head received error write on),
but i can't with two core...is it possibile run it???



There are other ways that do not know??


thanks

[debcox]

Perhaps this is explained elsewhere on the ROMS forum, but I'm not sure that it is possible to run a program on 1 core of a dual core processor. How do you know that you are not already using both cores?

Could someone more knowledgeable about these kinds of issues clarify this?

[jcwarner]

I am not sure the exact state of this discussion, but here is some hopefully helpful information.
IF you compile with MPI, you can run the program with 1, 2, 3, or however many processors that you have. But you need to set the number of tiles correctly.
For a simulation using ROMS only, the Number I * Number J tiles needs to = the total number of mpi processors requested.
For a coupled simulation of roms + swan, the number of swan + roms processors needs to = the total number of mpi processors requested. These are set in the coupling.in file.