------- Comment From [email protected] 2017-08-16 14:37 EDT------- > Did this issue start happening after an update/upgrade? Was there a prior > kernel version where you were not having this particular problem?
First time I've noticed this issue was with a 4.11 kernel in Ubuntu 17.10 about a month ago. A prior kernel version that didn't show this bug is the 4.10 kernels from Ubuntu 17.04. The bug happens when you have a kernel with commit 943db62c316c578f8e2cc6fb81a5f641096b29bf (first introduced in 4.11 afaik) and a kernel config with CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE=y. The solution is either change the kernel config to remove/disable this option or Nathan's patch that fixes the issue without the need to disable the option: ------ commit 1a367063ca0c1c6f6f54b5abd7b4836b0866a07b Author: Nathan Fontenot <[email protected]> Date: Wed Aug 2 14:03:22 2017 -0400 powerpc/pseries: Check memory device state before onlining/offlining ------ This commit was approved by the PPC kernel maintainer but it isn't present upstream yet in both Linus and Ubuntu kernel trees. > Would it be possible for you to test the latest upstream kernel? Refer to > https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.13 > kernel[0]. > The bug is still happening. As I've said above, the fix isn't present in the kernel code yet. > If this bug is fixed in the mainline kernel, please add the following tag > 'kernel-fixed-upstream'. > > If the mainline kernel does not fix this bug, please add the tag: > 'kernel-bug-exists-upstream'. > At this moment, kernel-bug-exists-upstream is the case here. Daniel -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1710922 Title: Ubuntu 17.10 ppc64el guest with MEMORY_HOTPLUG_DEFAULT_ONLINE=y gets a "kernel BUG at mm/memory_hotplug.c:2185" when hotplugging LMBs with QEMU upstream To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1710922/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
