If the Mac uses swap, then Linux can use the same swap to.
Let’s say theoretically, you have the following.
sda1 Mac
sda2 Vista
sda3 openSUSE
You still have room for one more partition. If your Mac uses a swap, then more than likely it’ll be like this.
sda1 swap
sda2 Mac
sda3 Vista
sda4 openSUSE
So all you’d have to do is tell openSUSE to mount that swap partition.
So now you have two ways you can do this.