open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello,

For the purpose of some developments I would like to use some MPI routines, or their TELEMAC equivalent such as P_SYNC, in some TELEMAC routines. The problem is that if I use MPI routines in some TELEMAC routines then I get errors. For example, I would like to use the MPI_BARRIER routine (or its TELEMAC equivalent P_SYNC) in read_fic_frliq.f but when I do so the run doesn't crash, it doesn't stop but it never gets to the end, it just freezes. It's the same if I use MPI_BCAST with a simple table such as A=(/1,2/). However if I want to use MPI routines in telemac2d.f there is, in this case, no problem.

My question is : is this a known issue ? Is there a limitation in TELEMAC for the use of MPI routines ? Is there a way to circumvent this problem ?

I use TELEMAC v6p3.

Regards

Hi Sébastien

As far as I know, it should works...
I use it recently in some developments without any problems.
Nevertheless, I suspect that you met a problem in the location of your MPI call.
Probably not all of your subdomains contains liquid boundaries so some process never reach the P_SYNC instruction...
You probably have to synchronize the processors at a higher level, at a place where you could be sure that all processors have to pass...

Hope this helps

PS: Note that we are not supported the use of old telemac version so it will be better for you, to move to the latest version...

Ahhhhh OK !!! I understand what the problem is !! And it explains why there was no problem with 2 procs and a problem with 3 procs..... Why didn't I think about this by myself ?! This looks so obvious now that you told me !

About the TELEMAC version I will wait to have a stable version of what I am currently working on and then I will switch to v7p1 version.

Thank you Christophe, see you