title: Look up table in linux+swap
body: <p>we write an image processing program in c++ that starts with making a 16MB look up table in Ram and we want it to be in Ram as long as our program is running!
  when we test in windows 7:making LUT takes approximately 4 seconds and reading from LUT and filling to matrices takes <strong>7 microseconds</strong>.</p>
  
  <p>But we have to run the software in Linux ,the results are confusing 
  making LUT takes approximately 3 seconds but reading from LUT and filling to matrices takes <strong>30 milliseconds</strong> !!!</p>
  
  <p>we guess it's because the LUT moves to swap !</p>
  
  <p>do you have any idea ?or if our guess is true is there anyway to keep LUT in ram in Linux ?!</p>