Piglit opens and closes a lot of files during a run, putting pressure
on FreeBSD's VFS. To keep Piglit smooth, you will have to increase the
default maxvnodes:
  sysctl kern.maxvnodes=$(($(sysctl -n kern.maxvnodes) * 2))

Instructions to use Piglit are available in:
  %%DOCSDIR%%/README.md

The same documentation is also available online:
  http://cgit.freedesktop.org/piglit/tree/README