COSMOMC with MPI & OpenMP

Use of Cobaya. camb, CLASS, cosmomc, compilers, etc.
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jayanti prasad
Posts: 14
Joined: October 21 2010
Affiliation: Inter-University Centre for Astronomy and Astrophysics (IUCAA)
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COSMOMC with MPI & OpenMP

Post by jayanti prasad » July 02 2011

I have two issues:

(1) I have not been able to compile COSMOMC with 'mpif90' with '-openmp' option for OpenMP. Basically I want CAMB to use OpenMP (as it does for an independent case). Any clue

(2) I can compile COSMOMC with 'ifort' with OpenMP option and it does work but gives very poor performance. I use 8 threads but never get more than 300 % CPU on a single node. .

Regards
Jayanti Prasad

Sheng Li
Posts: 57
Joined: May 26 2009
Affiliation: University of Sussex
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COSMOMC with MPI & OpenMP

Post by Sheng Li » July 04 2011

did i reply you? but where is my reply?

Sheng Li
Posts: 57
Joined: May 26 2009
Affiliation: University of Sussex
Contact:

Re: COSMOMC with MPI & OpenMP

Post by Sheng Li » July 04 2011

jayanti prasad wrote:I have two issues:

(1) I have not been able to compile COSMOMC with 'mpif90' with '-openmp' option for OpenMP. Basically I want CAMB to use OpenMP (as it does for an independent case). Any clue
Try ignoring option -openmp just for mpirun or mpif90.
But add it to F90Flag or FFlag for compiler (in your case, ifort)

mpirun stuffs are just a wrapper, i think.
(2) I can compile COSMOMC with 'ifort' with OpenMP option and it does work but gives very poor performance. I use 8 threads but never get more than 300 % CPU on a single node. .

Regards
Jayanti Prasad
i think the above solution will help if you can compile through.

And before doing that, make sure you can find mpirun/mpif90. Just type 'which mpirun' in term, then also you need to know which compiler and suffix will be linked by mpirun, just type 'mpirun -show' or mpirun without argument in term.

You will sort it yourself i think.
good luck.

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