Change the swap memory size in Raspeberry

I've been puzzled by a failure in the Rails on Ruby setup inside the Pi. After searching I found this page and it works fine:
Raspbian uses dphys-swapfile, which is a swap-file based solution instead of the "standard" swap-partition based solution. It is much easier to change the size of the swap.

• The configuration file is:

/etc/dphys-swapfile 

• The content is very simple. By default my Raspbian has 100MB of swap:

CONF_SWAPSIZE=100

• If you want to change the size, you need to modify the number and restart dphys-swapfile:

/etc/init.d/dphys-swapfile stop
/etc/init.d/dphys-swapfile start

 
The last step didn't work for me. Instead, I had to restart the Pi.