Hi Joe, I did verify this again with the below kernels and results: - 4.8.0-22 16.10 kernel - kdump through NMI on 4 CPU cores doesn't work - VM gets stuck and there is no crash file nor a reboot. - 4.9.0-040900RC8 kernel from ubuntu mainline - kdump through NMI works fine when using single core or SMP *with 4 cores*. Using 8 cores on this kernel, triggering the crash will result in the same bad behavior as from the GA kernel. I don't see any crash messages on the console, and the VM will just hang. Will have to do more debugging on this new pattern.
All tests have been done with crashkernel=512M and 2GB RAM for the VM. 4.9 also just got released, as of 11/12. -- 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/1630924 Title: Kdump through NMI SMP and single core not working on Ubuntu16.10 Status in linux package in Ubuntu: Confirmed Status in linux source package in Yakkety: Confirmed Bug description: During some tests I've encountered an issue with kdump through NMI SMP and single core. After kdump configuration, when I trigger the crash through an NMI call from the host, the VM will panic, however it will not write the vmcore dump files and neither reboot. REPRO STEPS: 1. configure kdump - crashkernel=512M-:384M /boot/grub/grub.cfg - USE_KDUMP=1 /etc/default/kdump-tools 2. after configuration reboot the VM 3. check kdump status - cat /sys/kernel/kexec_* - service kdump-tools status 4. configure NMI - sysctl -w kernel.unknown_nmi_panic=1 5. trigger a crash from host - Debug-VM -Name $vmName -InjectNonMaskableInterrupt -ComputerName $hvServer -Force This case also applies to: -Ubuntu 16.10 generation 2(kernel version: 4.8.0-17-generic) -Ubuntu 16.04.1(kernel: 4.4.0-38-generic) -Ubuntu 14.04.5(kernel: 3.19.0-69-generic) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1630924/+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
