I think that pretty surely is the reason that Arch is different. That flag will cause Xen to use its own paravirtualized spinlocks which I am suspecting of causing the problems (in some way related to having tasks in taskgroups which autogroup does automatically to happen). This seems, when the conditions are right, to cause a deadlock situation.
For now (as figuring out the problem and getting a solution could prove to take a bit) I think the best work-around for affected production systems is "noautogroup". That could then be removed as soon as we got a proper solution. -- 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 [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
