how to release vm swap file without reboot

Hi all

I got a 128GB vswp file that I would like to clean out and reduce the size somewhat and I can't do a reboot. Which is what I find to the most common way of clearing that file.

I also tried setting memory reservation but that didn't work because all the server's memory is going to this VM anyway.

So any ideas on what can I do short of finding a maintenance window?

davy