swap you should have in a partition dedicated to that as far as I am concerned.
I give you my setup, it will help you understand...
sudo mac-fdisk /dev/hda
Command (? for help): p
# type name length base ( size ) system
/dev/hda1 Apple_partition_map Apple 63 @ 1 ( 31.5k) Partition map
/dev/hda2 Apple_Bootstrap untitled 1954 @ 64 (977.0k) NewWorld bootblock
/dev/hda3 Apple_UNIX_SVR2 untitled 37345704 @ 2018 ( 17.8G) Linux native
/dev/hda4 Apple_UNIX_SVR2 swap 1722358 @ 37347722 (841.0M) Linux swap
Block size=512, Number of Blocks=39070080