Hi @ddstreet, thanks for the update. We unfortunately weren't able to reproduce this on your test kernel, and have since moved to a newer kernel version for other reasons.
However, I can confirm that on the affected machine types, and only the affected machine type, we see a memory range in `/proc/iomem` that ends off of a multiple of 2M. Again, we do not see this on any other machines. I've attached `/proc/iomem` and `/proc/zoneinfo` from an affected machine (currently running an LTS backport kernel: Linux [redacted] 3.19.0-33-generic #38~14.04.1-Ubuntu SMP Fri Nov 6 18:17:28 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux ) I'm pretty sure they show the kind of mismatch you're talking about; iomem shows 100000000-f0fffefff : System RAM f0ffff000-f0fffffff : RAM buffer f10000000-f17ffffff : System RAM But the “Node 0 Normal” zone, judging from (start_pfn, start_pfn+spanned) spans 100000000-f18000000. The machine in question is a c4.8xlarge in EC2. ** Attachment added: "iomem.txt" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1497428/+attachment/4529726/+files/iomem.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1497428 Title: kernel BUG at /build/buildd/linux-3.13.0/mm/page_alloc.c:968 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1497428/+subscriptions -- ubuntu-bugs mailing list firstname.lastname@example.org https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs