I'm sorry I meant OpenMP threads are able to spawn MKL processes On Fri, Apr 7, 2023 at 8:29 PM Dave May <dave.mayhe...@gmail.com> wrote:
> > > On Fri 7. Apr 2023 at 07:06, Astor Piaz <appiazzo...@gmail.com> wrote: > >> Hello petsc-users, >> I am trying to use a code that is parallelized with a combination of >> OpenMP and MKL parallelisms, where OpenMP threads are able to spawn MPI >> processes. >> > > Is this really the correct way to go? > > > Would it not be more suitable (or simpler) to run your application on an > MPI sub communicator which maps one rank to say one compute node, and then > within each rank of the sub comm you utilize your threaded OpenMP / MKL > code using as many physical threads as there are cores/ node (and or hyper > threads if that’s is effective for you)? > > Thanks, > Dave > > I have carefully scheduled the processes such that the right amount is >> launched, at the right time. >> When trying to use my code inside a MatShell (for later use in an FGMRES >> KSPSolver), MKL processes are not being used. >> >> I am sorry if this has been asked before. >> What configuration should I use in order to profit from MPI+OpenMP+MKL >> parallelism? >> >> Thank you! >> -- >> Astor >> >
