> On Aug 20, 2020, at 8:31 AM, Stefano Zampini <stefano.zamp...@gmail.com> > wrote: > > Can you add a MPI_Barrier before > > ierr = MatAssemblyBegin(aij->A,mode);CHKERRQ(ierr); >
With a MPI_Barrier before this function call: — three of the processes have already hit this barrier, — the other 5 are inside MatStashScatterGetMesg_Private -> MatStashScatterGerMesg_BTS -> MPI_Waitsome(2 processes)/MPI_Waitall(3 processes) > Also, in order to assess where the issue is, we need to see the values (per > rank) of > > ((Mat_SeqAIJ*)aij->B->data)->nonew > mat->was_assembled > aij->donotstash > mat->nooffprocentries > I am working to get this information. > Another question: is this the first matrix assembly of the code? Yes, this is the first matrix assembly in the code. > If you change to pc_none, do you get the same issue? Yes, with "-pc_type none” the code is stuck at the same spot.