First, confirm if zswap is supported (“y” means yes)

# cat /boot/config-`uname -r` | grep -i zswap
CONFIG_ZSWAP=y

Next, check if it’s enabled (“N” means no)

# cat /sys/module/zswap/parameters/enabled
N

If the above result is “N” (no), then enable it

echo Y | sudo tee /sys/module/zswap/parameters/enabled

Now check again and it should be enabled

# cat /sys/module/zswap/parameters/enabled
Y