Stefan, the kernel version in the Amazon Linux AMI that Matt pointed at
is 3.2.21-1.32.6.amzn1.x86_64, so it is very close to comparable with
the affected Ubuntu kernel (yes, there are source differences, but they
at least have a merge base of 3.2.21 so they share significant lineage).
I was able to reproduce the deadlock on the latest Ubuntu 12.04 PV AMI
(ami-3d4ff254), running linux-image-3.2.0-31-virtual (3.2.0-31.50). It
didn't take very long until the thing was totally frozen (less than a
GiB of space on /mnt consumed).
I'm currently trying something new now. I've built the same Ubuntu
kernel from git (Ubuntu-3.2.0-31.50-0-g0d9657d), but instead of using
the Ubuntu kernel config, I grabbed the kernel config used in the Amazon
Linux AMI Matt mentioned (ami-aecd60c7). So far it hasn't keeled over
(at 13GiB right now, running for about 1 hour 20 minutes).
I'm looking through the config diff right now, from Ubuntu config ->
Amazon Linux config. They have significant differences, but mostly in
the drivers selected. These are some highlights that stand out to me:
CONFIG_DEFAULT_IOSCHED="noop" instead of "deadline"
CONFIG_HZ=1000 instead of CONFIG_HZ=250
No CONFIG_IOSCHED_{DEADLINE,CFQ}
No CONFIG_COMPACTION
No CONFIG_CLEANCACHE
No CONFIG_CFS_BANDWIDTH
No CONFIG_SCHED_AUTOGROUP
No CONFIG_CGROUP_MEM_RES_CTLR*
No CONFIG_XEN_SELFBALLOONING
No hugepage-related options (HUGETLBFS, TRANSPARENT_HUGEPAGE, etc)
Numerous device drivers not relevant to a VM are disabled (CONFIG_DVB_*,
CONFIG_VIDEO_*, CONFIG_SND_*, etc), though these code paths are largely
not exercised in the guest regardless of whether they're built, and I'd
find it difficult to believe one of these causes the deadlock.
I suspect the faulting path is hit by one of the above config options.
I'll continue my investigation.
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1011792
Title:
Kernel lockup running 3.0.0 and 3.2.0 on multiple EC2 instance types
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1011792/+subscriptions
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
