B..2 Running

CHARM++ distribution contains a script called charmrun that makes the job of running AMPI programs portable and easier across all parallel machines supported by CHARM++. charmrun is copied to a directory where an AMPI prgram is built using charmc. It takes a command line parameter specifying number of processors, and the name of the program followed by AMPI options (such as number of chunks to create, and the stack size of every chunk) and the program arguments. A typical invocation of AMPI program pgm with charmrun is:

> charmrun pgm +p16 +vp32 +tcharm_stacksize 3276800

Here, the AMPI program pgm is run on 16 physical processors with 32 chunks (which will be mapped 2 per processor initially), where each user-level thread associated with a chunk has the stack size of 3,276,800 bytes.