Hi, My PETSc based application can work correctly, but after system updating when I use the same commands: >lamboot >mpiexec -np 4 application
It seems only one processor works. Then I test it using the following code, ********** PetscErrorCode ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr); COUT << "This is processor : " << rank << ENDL; Use command: mpiexec -np 4 application, The output is: This is processor : 0 This is processor : 0 This is processor : 0 This is processor : 0 ********* Thanks for your help. Yixun
