1.3 High-Level Description of PPW's Workflow

In designing PPW, we have strived to make day-to-day usage of our tool to be as painless as possible. Rather than require users to completely modify their build process, we have opted to use compiler wrapper scripts that take care of the mundane details of setting up PPW's compilation environment. Also, our tool has been designed to work with both batch-processing and interactive machines, so we have taken the approach of providing a text-based interface (via the ppwprof command) for viewing performance data on your parallel machine, in addition to a graphical frontend that can run both on your parallel machine (the ppw command) and on your workstation.

In general, and assuming you have a working installation of PPW (see Installing PPW), to use PPW you generally perform these steps:

• Instead of using upcc or cc (ie, your regular compilers), compile your application using ppwupcc for UPC programs, ppwshmemcc for SHMEM programs, or ppwcc for sequential C programs.
• Prefix your regular run command with ‘ppwrun --profile’ to gather profile data or ‘ppwrun --trace’ to gather trace data.
• View performance information using ppwprof or by transferring the PAR data file to your workstation and using the PPW GUI. If you've collected trace data, then convert your PAR data file using one of the conversion utilities and view your performance data in Jumpshot or Vampir.
• Update your code and run your program again to see how your application's performance changed.
• Repeat until your application is fast/efficient enough.

More details on each of the steps listed above can be found in later parts in this manual.