Comment 0 for bug 1653636

On powering my PC up after the holiday break I got a welcome back in the form of a kernel panic. I had completed some upgrades before the holiday and was seeing a restart to use the newly upgraded packages message.

When the PC powered on the Caps Lock and Scroll Lock lights on my keyboard were blinking. After passing through grub and attempting to boot the kernel the boot message ended with the following message (typed out by me by hand, please see the attached photograph of the screen for more details):

Kernel Offset: disabled
---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at arch/x86/kernel/smp.c:125 native_smp_send_reschedule+0x60/0x70(
Modules linked in:
CPU: 0 PID 1: Comm: swapper/0 Not tainted 4.4.21 #1
Hardware name: Gigabyte Technology Cp., Ltd. H81M-DS2V/H81M-DS2V, BIOS F6 08/11/2015
 ...
Call Trace:
 ... dump_stack
 ... warn_slowpath_common
 ... warn_slowpath_null
 ... native_smp_send_rescheduale
 ... trigger_load_balance
 ... scheduler_tick
 ... ? tick_sched_handle.isra
 ... update_process_times
 ... tick_sched_handle.isra

I can type out more of the message if people want but I think the chances of my typing it all in correctly are slim.

I tried to boot using the (recovery mode) version of 4.4.21 and the .old version of 4.4.21 that seemed to have appeared from somewhere. To my eye the problem looked the same in each version. Once I selected 4.4.0-57-generic I was able to complete the boot and begin reporting this bug.

If there are any more steps I can take to aid diagnosis please let me know.