Can you also give the latest 3.16 upstream stable kernel a test? This will tell us if the fix in mainline already made it's way into stable updates:
http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.16.6-utopic/ ** Also affects: linux (Ubuntu Utopic) Importance: Undecided Status: New ** Changed in: linux (Ubuntu Utopic) Importance: Undecided => Medium ** Changed in: linux (Ubuntu Utopic) Status: New => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1386473 Title: Not using all cores after upgrade to 14.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1386473/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs