As you can see in the dmesg log it happens when the kernel is initializing the second CPU core. I believe this started after the AMD microcode update against Spectre/Meltdown mitigations.
Should be reported also to https://bugzilla.kernel.org/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1856433 Title: do_IRQ: 1.55 No irq handler for vector To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1856433/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
