I have removed zfs and migrated back to mdadm and was able to install an upstream kernel (4.10.17-041017-generic) and this issue persists.
** Tags added: kernel-bug-exists-upstream -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1694800 Title: Frequent Core Lock To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1694800/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs