title: Limit memory on a Docker container doesn't work
body: <p>I am running the last version of Docker on top of Ubuntu&nbsp;13.04 (Raring Ringtail):</p>
  
  <pre><code>root@docker:~# docker version
  Client version: 0.6.6
  Go version (client): go1.2rc3
  Git commit (client): 6d42040
  Server version: 0.6.6
  Git commit (server): 6d42040
  Go version (server): go1.2rc3
  Last stable version: 0.6.6
  </code></pre>
  
  <p>But when I start the container,</p>
  
  <pre><code>root@docker:~# docker run -m=1524288 -i  -t ubuntu /bin/bash
  root@7b09f638871a:/# free -m
               total       used       free     shared    buffers     cached
  Mem:          1992        608       1383          0         30        341
  -/+ buffers/cache:        237       1755
  Swap:         2047          0       2047
  </code></pre>
  
  <p>I don't see any limiting from any kind, and my kernel has the cgroups memory limit enabled:</p>
  
  <pre><code>kernel /boot/vmlinuz-3.8.0-33-generic ro console=tty0 root=/dev/xvda1 cgroup_enable=memory swapaccount=1
  </code></pre>
  
  <p>What obvious thing am I missing here?</p>