[Trilinos-Users] Error while using ILU smoothers in parallel along with AMG in ML

SRIRAMKRISHNAN MURALIKRISHNAN sriramkrishnan at utexas.edu
Thu Jul 26 16:40:55 EDT 2018

Dear all,

I am trying to solve the linear system arising from 3D MHD simulations using AMG preconditioned GMRES in trilinos. I want to use ILU-0 as the smoother for AMG with overlap 1 as it gave the least number of iterations for the problem I am solving. However, I am getting segmentation fault with the ILU smoothers every once in a while (i.e. sometimes it works and sometimes not) with openmpi and with intel mpi it never works and always gives the segmentation error.
I am using Trilinos 12.12.1 and here are the list of parameters I set

   Teuchos::ParameterList MLList;
    Teuchos::ParameterList &smList = MLList.sublist("smoother: ifpack list");
    MLList.set("aggregation: type","Uncoupled");
    MLList.set("aggregation: threshold",0.01);
    MLList.set("smoother: type","ILU");
    MLList.set("coarse: type","Amesos-KLU");
    MLList.set("smoother: ifpack overlap",1);
    MLList.set("smoother: ifpack level-of-fill",0.0);
    MLList.set("smoother: sweeps",4);
    smList.set("reuse numeric factorization",1);
    MLList.set("energy minimization: enable",true);
    MLList.set("ML output",10); 

This is the error I am getting

Primary job  terminated normally, but 1 process returned
a non-zero exit code. Per user-direction, the job has been aborted.
mpirun noticed that process rank 0 with PID 0 on node wireless-10-145-120-208 exited on signal 11 (Segmentation fault: 11).

Can anyone please help me what I might be doing wrong. I have no problem using the default Chebyshev smoothers, however the number of iterations with Chebyshev
smoother is large and that is the reason I want to use ILU smoother.

Any help is very much appreciated.


Sriramkrishnan Muralikrishnan

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