proton, Dale Hamel and all. Please test this proposed kernel. Details can be found in comment #28.
Eric -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1572630 Title: boot-time kernel panic introduced in 4.4.0-18, not present in 4.4.0-15 Status in linux package in Ubuntu: Fix Released Status in linux-lts-xenial package in Ubuntu: Invalid Status in linux source package in Trusty: Invalid Status in linux-lts-xenial source package in Trusty: In Progress Status in linux source package in Xenial: Fix Committed Status in linux-lts-xenial source package in Xenial: Invalid Status in linux source package in Yakkety: Fix Released Status in linux-lts-xenial source package in Yakkety: Invalid Bug description: [Impact] At boot-time, the kernel will panic somewhere in 'blk_mq_register_disk', a snippet of the track is below, and full panic dump is attached. The panic dump was collected via serial console, as the kernel panics so early that we cannot kdump it. [ 2.650512] [<ffffffff813ac8a6>] blk_mq_register_disk+0xa6/0x160 [ 2.656675] [<ffffffff813a1b44>] blk_register_queue+0xb4/0x160 [ 2.662661] [<ffffffff813af53e>] add_disk+0x1ce/0x490 [ 2.667869] [<ffffffff815477e0>] loop_add+0x1f0/0x270 [Test Case] At boot-time, the kernel will panic somewhere in 'blk_mq_register_disk', a snippet of the track is below, and full panic dump is attached. [Regression Potential] * Fix implemented upstream starting with v4.6-rc1 * The fix is fairly straightfoward given the stack trace. * The fix is hard to verify, but user "Proton" was able to confirmed that upstream mainline 4.6-rc1 solve the situation and that the test kernel I have provided including the fix solves this particular problem as well. Confirmation by Proton : https://bugs.launchpad.net/ubuntu/+source/linux-lts-xenial/+bug/1572630/comments/23 [Other Info] * https://lkml.org/lkml/2016/3/16/40 * http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e0e827b9 * http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=897bb0c7 [Original Description] We discovered a pretty serious regression introduced in 4.4.0-18. At boot-time, the kernel will panic somewhere in 'blk_mq_register_disk', a snippet of the track is below, and full panic dump is attached. The panic dump was collected via serial console, as the kernel panics so early that we cannot kdump it. [ 2.650512] [<ffffffff813ac8a6>] blk_mq_register_disk+0xa6/0x160 [ 2.656675] [<ffffffff813a1b44>] blk_register_queue+0xb4/0x160 [ 2.662661] [<ffffffff813af53e>] add_disk+0x1ce/0x490 [ 2.667869] [<ffffffff815477e0>] loop_add+0x1f0/0x270 This seems somewhat similar to https://lkml.org/lkml/2016/3/16/40, but the trace is not identical. We discovered this issue when we were experimenting with linux- generic-lts-xenial from trusty-updates on a 14.04 installation. When we installed it, 4.4.0-15 was the current package, and it worked fine and provided a large amount of improvements for us. Background security updates installed 4.4.0-18, and this updated and grub and became the default kernel. On a reboot, the node panics about 2 seconds in, resulting in a machine in a dead state. We were able to boot a rescue image and roll bac kto 4.4.0-15, which works nicely. We currently have pinning on 4.4.0-15 to prevent this problem from coming back, but would prefer to see the problem fixed. I'll attach lspci, lshw, and dmidecode for our hardware as well, but this is happening on pretty vanilla supermicro nodes. We are able to consistently reproduce it on our hardware. It is not reproducible in EC2, only on metal. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1572630/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
