Thanks for the pointer to the patch, willmo. Now I understand why the bug existed in Utopic and not in upstream 3.16.6.
Utopic has the following SAUCE commit: commit 8ee41919feea10de065e3102de4cbf0c57fc60ea Author: Dave Hansen <dave.han...@linux.intel.com> Date: Thu Sep 18 12:33:34 2014 -0700 UBUNTU: SAUCE: x86, sched: Add new topology for multi-NUMA-node CPUs Which is upstream commit: cebf15eb. The SAUCE commit adds this line, which is what causes this bug: if (match_die(c, o) == !topology_same_node(c, o)) Commit 728e565 fixes this bug by changing the line to: if (match_die(c, o) && !topology_same_node(c, o)) I built a Utopic test kernel with a cherry-pick of 728e565. The test kernel can be downloaded from: http://kernel.ubuntu.com/~jsalisbury/lp1386473/ Can you test this kernel and confirm if it fixes this bug? Note, you will need to install both the linux-image and linux-image-extra .deb packages. -- 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