I don't explicitly use the communicator PETSC_COMM_WORLD. Instead I used MPI_COMM_WORLD, which according to the manual should be the same.
However, I create two new communicator from MPI_COMM_WORLD using MPI_Comm_split(). LBM_Comm and FEA_Comm. Only the ranks in FEA_Comm make use of KSP solver and PARMETIS. When creating objects for mesh partitioning (MatPartitioningCreate()) and solver (KSPCreate()), I use the new communicator FEA_Comm. Would this have any effect on the command line options? Regards Irfan I am not sure what you are doing, but something is wrong in this code. Using different communicators does not have much to do with options. Any object (like a KSP) can be created using a subcomm of WORLD. Are you setting PETSC_COMM_WORLD to something different? That is not necessary here. Matt Thank you Irfan ----- Original Message ----- From: "Matthew Knepley" < [email protected] > To: "PETSc users list" < petsc-users at mcs.anl.gov > Sent: Tuesday, November 24, 2009 8:03:00 PM GMT -05:00 US/Canada Eastern Subject: Re: Multiple communicators On Tue, Nov 24, 2009 at 6:59 PM, < irfan.khan at gatech.edu > wrote: Hello Does the procedure for providing command line options and to obtain profiling data through -log_summary change if there are multiple MPI communicators in a petsc code? There is always WORLD, so it should be fine unless I misunderstand your question. Matt If so, can somebody point me to information, references on how to provide command line options if there are multiple communicators? Thank you Irfan -- PhD Candidate G.W. Woodruff School of Mechanical Engineering Georgia Institute of Technology Atlanta, GA (30332) -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener -- PhD Candidate G.W. Woodruff School of Mechanical Engineering Georgia Institute of Technology Atlanta, GA (30332) -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener -- PhD Candidate G.W. Woodruff School of Mechanical Engineering Georgia Institute of Technology Atlanta, GA (30332) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20091124/d6cdbbed/attachment.htm>
