** Description changed: + SRU Justification: + + Impact: The version of Xen patches we currently use for the ec2 kernel + have a serious flaw in the handling of nested spinlocks. This can result + in a complete deadlock under certain workloads. + + Fix: The spinlock handling code has been substantially restructured in + later versions of the patchset. The changes backport this but also + enable the use of ticket-spinlocks (as we do now) when compiling with + the compatibility level we use. + + Testcase: Not easy to reproduce. But feedback with the patchset applied + (see comment #32) look good. + + -- + After running for some indeterminate period of time, the 2.6.32-341-ec2 and 2.6.32-342-ec2 kernels stop responding when running on m2.2xlarge EC2 instances. No console output is emitted. Stack dumps gathered by examining CPU context information show that all VCPUs are stuck waiting on spinlocks. This could be a deadlock in the scheduling code. ProblemType: Bug DistroRelease: Ubuntu 10.04 Package: linux-image-2.6.32-341-ec2 2.6.32-341.42 ProcVersionSignature: User Name 2.6.32-341.42-ec2 2.6.32.49+drm33.21 Uname: Linux 2.6.32-341-ec2 x86_64 Architecture: amd64 Date: Fri Feb 10 01:56:17 2012 Ec2AMI: ami-55dc0b3c Ec2AMIManifest: (unknown) Ec2AvailabilityZone: us-east-1c Ec2InstanceType: m1.xlarge Ec2Kernel: aki-427d952b Ec2Ramdisk: unavailable ProcEnviron: - LANG=en_US.UTF-8 - SHELL=/bin/bash + LANG=en_US.UTF-8 + SHELL=/bin/bash SourcePackage: linux-ec2
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/929941 Title: Kernel deadlock in scheduler on multiple EC2 instance types To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-ec2/+bug/929941/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
