Greetings, I am new to petsc and not sure how to interpret the result I get when running petsc example codes (bratu problem and hello world) in an SGI Altix 1300 cluster. Any help will be greatly appreciated!
I compile the petsc code using a makefile that came with the petsc distribution, submit the job to the queue using pbspro, and run using mpirun. The solution returned by running the bratu problem ($PETSC_DIR/src/snes/examples/tutorials/ex5f90.F) looks correct, but I am not sure if petsc is using all processors supplied to it by mpirun. MPI_COMM_SIZE always returns a size of 1 and MPI_COMM_RANK always returns rank 0, when I call these routines from inside my code, despite using a command like mpirun -n 16 -machinefile $PBS_NODEFILE myexecutable.exe in my submit shell script. I get similar results when I run hello world with Petsc. It prints 16 lines displaying rank=0 and size=1, when run with 16 processors. Run just with mpi, helloworld prints the size and ranks as expected, i.e. 16 different lines with size 16 and ranks from 0 to 15. Am I correct in assuming that petsc is somehow not able use the version of mpirun implemented in vltmpi? I reran the petsc using the install shell script given below, but it did not help export PETSC_DIR=$PWD ./config/configure.py --with-mpi-dir=/opt/vltmpi/OPENIB/mpi.icc.rsh/bin make all test Sash Hier-Majumder -- www.geol.umd.edu/~saswata
