PHYCS 6730 Lab Exercise: Introduction to PBS and MPI

Exercise 1. Running the code in batch mode on icebox.

Change the e-mail address in the file hello.pbs. Then run the command

  qsub hello.pbs

to run the job interactively. See the PBS handout for information about monitoring the job status and for other details about the job script file.

When your job is done, copy the contents of the file output to your answer file to hand in.

Exercise 2. Broadcast

Look up MPI_Bcast in the MPI documentation .

Modify the code so that only node 0 sets a variable to 42, but then it broadcasts the result to all the other nodes. Then have all the nodes write a message saying "node [this_node] received [value]", substituting the node number and value received.

Hint: Put the assignment statement inside an if(this_node==0) block, so it gets assigned only on node 0. But the MPI_Bcast command is supposed to run on all the nodes. Node 0 does the sending if you specify it in the argument as the "root" node.

Hand in your output.