From: Alex Gutteridge <alexg@...>
Date: 2007-08-07T09:35:32+09:00
Subject: Re: [ANN] Free RAM 1.0

On 7 Aug 2007, at 07:06, Ari Brown wrote:

> Hey!
>
> Despite your best efforts, Todd, I managed to create a tool which  
> will free RAM to be used by other programs.
>
> At the moment, it is only usable on *nix machines (BSD, Linux, and  
> Mac). Will add Windows support soon.
> move it to /bin and save it as free_ram
>
> Usage: free_ram TIME
> TIME is the amount of time you want Ruby to spend clearing the RAM.  
> A good amount is about 20. I can clear a large amount of RAM with  
> that.
>
> http://www.aribrown.com/ruby/free_ram.rb

Other people have explained why this really isn't such a great idea,  
but in the spirit of experimentation...

If you want a portable version why not just:

require 'timeout'

z = ''
timeout(25){ while(true) do z << 0.chr * (2 ** 24) end}

Or for the 'moar power!!11!' user how about a RubyInline version:

require 'inline'

class IWantA
   inline do |builder|
     builder.c "
     int way_to_die(int size){
       return malloc(size);
     }"
   end
end

while(IWantA.new.way_to_die(2 ** 12) != 0)
end

Both managed to shunt almost every other process into swap in a few  
seconds. Enjoy!

Alex Gutteridge

Bioinformatics Center
Kyoto University