How can you mmap in parallel for faster file reading?

I am working through this code and have the mmap working now, but I am wondering if I can use mmap in parallel and if so, how to accomplish it. Suppose I have my data on a parallel file system (GPFS, RAID0, whatever) and I want to read it using n processes.

How could I, for example, have each processor read 1/nth contiguous block of the data into memory? Or, alternatively, read every nth memory block (1 B, 1 MB, 100 MB, 1 GB, whatever I choose for optimization) into memory?

I am assuming a posix file system here.

via Chebli Mohamed