Hi, I'm curious about which version of dkms package do you have? The build process itself is parallel by default since dkms/2.2.0.3-4.
It would take a lot of time at configure stage because versions prior to zfs-linux/0.8.3-1 suffer from the non-parallel KABI check, and if you have plenty of cores on the system then it gives an impression that configure takes ages but the actual build finishes in seconds. Regards, Aron