** Also affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Also affects: linux (Ubuntu Xenial)
Importance: Undecided
Status: New
** Also affects: linux-lts-xenial (Ubuntu Xenial)
Importance: Undecided
Status: New
** Also affects: linux (Ubuntu Yakkety)
Importance: Undecided
Status: New
** Also affects: linux-lts-xenial (Ubuntu Yakkety)
Importance: Medium
Assignee: Eric Desrochers (slashd)
Status: In Progress
** Changed in: linux (Ubuntu Xenial)
Status: New => Fix Committed
** Changed in: linux (Ubuntu Yakkety)
Status: New => Fix Released
** Changed in: linux-lts-xenial (Ubuntu Xenial)
Status: New => In Progress
** Changed in: linux-lts-xenial (Ubuntu Xenial)
Status: In Progress => Invalid
** Changed in: linux-lts-xenial (Ubuntu Yakkety)
Status: In Progress => Invalid
** Also affects: linux (Ubuntu Trusty)
Importance: Undecided
Status: New
** Also affects: linux-lts-xenial (Ubuntu Trusty)
Importance: Undecided
Status: New
** Changed in: linux-lts-xenial (Ubuntu Trusty)
Status: New => In Progress
** Changed in: linux (Ubuntu Trusty)
Status: New => Invalid
** Changed in: linux-lts-xenial (Ubuntu Yakkety)
Assignee: Eric Desrochers (slashd) => (unassigned)
** Changed in: linux (Ubuntu Xenial)
Assignee: (unassigned) => Eric Desrochers (slashd)
** Changed in: linux-lts-xenial (Ubuntu Trusty)
Assignee: (unassigned) => Eric Desrochers (slashd)
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You received this bug notification because you are a member of नेपाली
भाषा समायोजकहरुको समूह, which is subscribed to Xenial.
Matching subscriptions: Ubuntu 16.04 Bugs
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
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