title: Resident Set Size (RSS) limit has no effect
body: <p>The following problem occurs on a machine running Ubuntu 10.04 with the 2.6.32-22-generic kernel: Setting a limit for the Resident Set Size (RSS) of a process does not seem to have any effect. I currently set the limit in Python with the following code:</p>
  
  <pre><code>import resource
  # (100, 100) is the (soft, hard) limit. ~100kb.
  resource.setrlimit(resource.RLIMIT_RSS, (100, 100))
  memory_sink = ['a']*10000000   # this should fail
  </code></pre>
  
  <p>The list, memory_sink, succeeds every time. When I check RSS usage with top, I can easily get the process to use 1gb of RAM, which means that the limit is not working. Do RSS limits not work with this kernel or distro? If it helps, resource.RLIMIT_NPROC (user process limit) does work.</p>