Comment 3 for bug 1847628

@colin-king

> A swapfile on ZFS is a bad idea. Swapped out pages get pushed through the vfs into zfs and each page of swap will be magnified in the number of free pages required to get this page out to disk.

currently, swap uses zvol in default. not a swapfile. (actually I also thinking swapfile is mistake of bad architecture..)

> ..there are known issues with swap on ZFS not working well on heavily memory loaded systems.

and also, i also see that article, and check it.
It was already optimised.