title: Do I need to keep a file open after calling mmap on it?
body: <p>I have a program that maps quite a few (100's) of sizable files 10-100MB each. I need them all mapped at the same time.</p>
  
  <p>At the moment I am calling <code>open</code> followed by <code>mmap</code> at the beginning of the program, followed by <code>munmap</code> and <code>close</code> at the end.</p>
  
  <p>Often I have to adjust the open files limit running <code>ulimit -n</code> before running the program.</p>
  
  <p>Question is do I actually need to keep the files open, or can I <code>open</code> <code>mmap</code> <code>close</code> do some large data processing then <code>munmap</code> when I'm finished.</p>
  
  <p>The man pages of <code>mmap</code> do not seem terribly clear to me on this one.</p>