[petsc-dev] Petsc "make test" have more failures for --with-openmp=1

[Eric Chamberland]

Hi Pierre!

On 2021-03-13 3:17 a.m., Pierre Jolivet wrote:
> Hello Eric,
> I’ve made an “interesting” discovery, so I’ll put back the list in c/c.
> It appears the following snippet of code which uses Allreduce() + 
> lambda function + MPI_IN_PLACE is:
> - Valgrind-clean with MPICH;
> - Valgrind-clean with OpenMPI 4.0.5;
> - not Valgrind-clean with OpenMPI 4.1.0.
> I’m not sure who is to blame here, I’ll need to look at the MPI 
> specification for what is required by the implementors and users in 
> that case.
>
> In the meantime, I’ll do the following:
> - update config/BuildSystem/config/packages/OpenMPI.py to use OpenMPI 
> 4.1.0, see if any other error appears;

ok,  I think it is a good idea since 4.1 is the "stable" version...


> - provide a hotfix to bypass the segfaults;

If OpenMPI guys fix the issue, maybe it will be included in the 4.1.1 
release (4.1.1rc1 is still open for modifications I think)...

An idea: I our code, we "block" compilations/usages of buggy MPIs 
versions...


> - look at the hypre issue and whether they should be deferred to the 
> hypre team.
Oh thanks for this! :)
>
> Thank you for the Docker files, they were really useful.
> If you want to avoid oversubscription failures, you can edit the file 
> /opt/openmpi-4.1.0/etc/openmpi-default-hostfile and append the line:
> localhost slots=12
> If you want to increase the timeout limit of PETSc test suite for each 
> test, you can add the extra flag in your command line TIMEOUT=180 
> (default is 60, units are seconds).
Noted, I will add this to my scripts and the dockerfiles too...
>
> Thanks, I’ll ping you on GitLab when I’ve got something ready for you 
> to try,

Thank you for all your work!

Eric

> Pierre
>
-- 
Eric Chamberland, ing., M. Ing
Professionnel de recherche
GIREF/Université Laval
(418) 656-2131 poste 41 22 42