====== stress ======
  * http://unix.stackexchange.com/a/99435/21185
  * http://www.cyberciti.biz/faq/stress-test-linux-unix-server-with-stress-ng/

<code bash>
stress --vm-bytes $(awk '/MemFree/{printf "%d\n", $2 * 0.9;}' < /proc/meminfo)k --vm-keep -m 1
</code>